Sectional furnace



Nov. 26, 1929. J. DOHERTY SECTIONAL FURNACE Filed March 21, 1923..mvlzxlllllllllllllllmllllIIIIII INVENTOR A TTORNEYS Patented Nov. 26,1929 UNHTED STATES PATENT p, @FFEQE JAMES DOI'IERTY, OF CHICAGO,ILLINOIS; ELLA MAUI) DOHERTY AND JAMES RUSSELL DOI-IERTY EXECUTORS OFSAID JAMES DOHERTY, DECEASED SECTIONAL FURNACE Application filed March21, 1923. Serial No. 626,486.

My invention relates to a sectional furnace of known type, which is madeup of an assembled series of hollow water-containing sections and inwhich it is sought to procure a complete combustion reaction and torender the furnace smokeless by the introduction of heated auxiliaryair, the structure and objects thus generally recited being'familiar inthis art.

My invention consists in an improved and simplified construction forbringing about these results in the most effective manner and which canbe incorporated in furnace design at low cost and without requiringcomplicated casting operations for any of the furnace sections. Moreparticularly the invention consists in air delivery means situated atthe throat, i. e. the firegas opening leading out of the firebox, andconstructed in such fashion that it substantially encircles said openingand delivers the air crosswise into the fire gas flow therethrough. Inthe furnace in which my invention is embodied, the front sections formthe firebox, the sections in rear thereof form the rear firebox wall andrear flue space and all of the sections provide overhead lines, ascustomary.

Referring to the drawings:

Fig. l is a side elevation of a furnace embodying my invention and inwhich the side walls of the assembled sections are in part broken awayto show internal structure in section.

Fig. 2 is an elevation of the section forming the rear of the firebox,parts of the air delivery box being shown in section.

Fig. 3 is a section on the line III-III of Fig. 2 looking in thedirection of the arrows, and

Fig. 4 is a detail perspective showing the interior of the airdistributing and delivery box.

The furnace thus illustrated is made up of a series of cast, hollow,water-containing sections 1 bolted together in the usual way andsupported by side base members 2 connected at the front and rear of thefurnace by transverse plates 3 and 4t and by an intermediate divisionalplate 5 constituting the rear wall of the ash pit, Usual doors anddampers are carried by the front plate 8. The several sections areprovided with aligned spaces forming the firebox 6, rear flue space 7overhead return side fiues 8 and central escape flue 9, the flow ofgases being as indicated by the arrows.

The front section 1 is provided with the usualfuel feed door 10 and flueclean-out doors 11, which permit access to all the overhead fines. Thethroat section, designated as l". constitutes the vertical rear wall 12of the firebox, which is hollow and water-containing, and extendsdownwardly to a unction with the base plate 5 or at least below the fuelbed. In this wall, preferably relatively near its top, is the throat ortransverse fire gas opening 13 leading from the firebox 6 to to the rearflue space 7, and in association with which I locate the improved meansfor distributing and delivering auxiliary air to the firegas flow. Thismeans forms a border for the throat and in its preferred form completelyencircles the same, being constituted of an open sided metal box-likestructure 14 having air-delivery openings 15 and attachment lugs 16. Itis preferably formed in two similar or identical parts or halves, asshown, which may be either cast or pressed of sheet metal, and whichwhen secured or bolted against the forward face of the water-containingbridge wall 12, as indicated in the drawings, form a loop-shaped airpassage with its series of outlets 15 opening inwardly or toward thefire gas flow through the throat. As thus mounted the openings 17 ateach end of the loop register with recesses or notches cast in theadjacent sides of the section 1*, constituting entrances for air to thebox dimet from atmosphere. Preferably, these entrances are equipped withthimbles or bushings 18 which are provided with dampers 19 to controlthe air admission. It will be understood that the main supply ofcombustion supporting air is through the perforated grate and fuel bedthereon, and that the air entering by way of the means just described isauxiliary thereto, and is heated by its contact with the air box 14:,which has imperforate metal wall structure projecting forward from thebridge wall into the fire flow to the throat to present said imperforatewall structure thereto to be heated thereby, the air delivery means ofthe box being located beyond this imperforate wall structure in thedirection of fire gas flow so that when the air is delivered and mixedwith the firegases in the throat 13 it is at a proper temperature tocombine with and burn the unconsumed fuel therein and thereby producethe; smokeless results desired. of the metal box 14 with the watercooled wall tends to keep it at a safe temperature. lhe most of theauxiliary air is delivered clownwards and upwards, and all of itcrosswise to the fire gas flow, it being desirable, to restrict orgraduate the exits 15 so that the distribution is substantially uniformfrom one side of the throat to the other. l Vhilc the structure of airbox, above describedis pre ferred, because of its simplicity andeffectiveness, itwill beunderstood that the advantages of the inventionmay be obtained by the use of other forms, similarly mounted or located.

The formation of the box l l in two parts is found to be of greatconvenience in assembling and in replacing, since in most cases theindividual parts can be removed (through the fuel feed door when theentire structure, if made, in onepi'ece, could not be removed withoutdisassembling the entire furnace, The box and the bushings 18 are madeand mounted independent so'that the box halves, or either of them, maybe installed or removed without disturbance of, or v restraint from,either busning. Of course, also, the two-part construction of the boxlowers the cost of manufacture, since the parts are identical and can bemadein, the same, dies or cast from the same patterns,

I claim;

1. A, sectional furnace made up of an as.- sembled series of cast hollowwater-containing sections having aligneo openings which constitute afirebox and fine space in rear thereof and in communication therewith, awater-cooled bridge wall formingthe rear wall of the firebox andlhavingan opening constituting the water-cooled throat, through which the firegases pass from the firebox to the flue space, and an air d livery boxlocated in the firebox in front of the front water-cooled face of saidbridge walhenclosing saidopening in the bridge wall and constructed toreceive and 'to deliver air around said opening to the entering currentof fire gases passing there through.

2. 'A sectional furnace made up of "an assembled series of cast hollowwater-containing sections having aligned openings which'constitute afirebox and flue space inrear thereof and in communication therewith, awatercooled bridge wall formingthe rear WilllfO'f the firebox and havingan opening constitutthe water-cooled throat through which the fire gasespass fromthe firebox to the flue At the same time the contact space, andan air delivery box adjacent said throat and exterior thereto andconsisting of an air conduit having an otherwise open side closed by avertical watencooled Wall of the bridge. wall section and means todeliver auxiliary air from said conduit to the fire gas flow.

3. A sectional furnace made up of an assembled series of east; hollowWater-con: taining sections having; aligned openings which constitute afirebox and flue space in rearmthereof and in communication therewith, awater-cooled bridge wall forming the rear wall of the firebox and havingan opening constituting the water-cooled throat through which the firegases pass from'thc fireboxto the flue space, and an air box made in twosections and having its rear side open, secured-tothe front of thebridge wall adj acent saidthroat with itsopen side against thewater-cooled bridge wall, and each of which, sections, may be putin-place or removed independently of the other, said sec tions, eachhaving in its fire-gas-contacted walls facing respectively the underside and the upper side of the fire gas flow air deliveryopenings andconstituting together means for delivering air upward and downwardathwart the current of fire gases passing through said box and.waterecooled throat;

4. In a sectional furnace, a metal air delivery box of loop form forenclosing a fire gas flow: space and having air delivery openings in itsinner wall which is posi tioned tobe contactedby fire gases and to facethe fire gas flow through i't, said box being provided with air inlet}openings and being also open atone side next said inner wall," andhavingmeans f0r attachment to the wallof a furnace section withits openside against the same.

5. A sectional furnace made up of an assembled series of, cast, hollowwatercontaining sections, having aligned openings which constitute afirebox andflue space in rear thereof 1 and in; communicationtherewith,-a water-cooled bridge wall forming the rear wall of thefirebox and havinganopening constituting the water-cooled-- throatthrough-which thefire gases pass from the firebox to thefiue space and aseparately made air delivery boxclamped to the bridge wall and havingits fire-gas-contacted-inner Walls in substantial registry with thewatercooled throat and havingone set of openings positioned to admit airfrom the atmosphere to the box and another set of openings positioned todeliver air throughsaid inner walls at intervals to said throat openingathwart the current of gases passing theret-hrough.

6.A sectional furnace made up of an assembled series of cast hollowwater-containing transverse sections having-aligned openingsconstitutinga-firebox and fiue space in'rearthereof and in communicationtherewith, one of said sections being a transverse water-containingbridge wall section having in its upper part a flue opening and beneaththe same a water-containing portion extending to a transverse watercooled firegas contacted throat through the section, and a separatelymade air delivery box extending transversely along the bridge Walladjacent the throat and having imperforate metal wall structureprojecting forward from the bridge wall into the fire gas flow to thethroat to present said ilnperforate wall structure thereto, said airdelivery box having beyond said imperforate wall structure in thedirection of fire gas flow means for delivering air to the fire gas flowthrough the throat.

In testimony whereof, I have signed this specification.

JAMES DOHERTY.

